System and method for sealing a vapor deposition source

ABSTRACT

A system and method for movably sealing a vapor deposition source is described. One embodiment includes a system for coating a substrate, the system comprising a deposition chamber; a vapor pocket located within the deposition chamber; and an at least one movable seal, wherein the at least one movable seal is configured to form a first seal with a first portion of a substrate, and wherein the first seal is configured to prevent a vapor from leaking past the first portion of the substrate out of the vapor pocket. In some embodiments, the movable seal may comprise a first flange, wherein the first flange forms a wall of the vapor pocket; and a second flange, wherein the second flange is configured to be movably disposed within a first groove of the source block.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No.12/762,024 filed on Apr. 16, 2010 and entitled “System and Method forSealing a Vapor Deposition Source” the disclosure of which is herebyincorporated by reference in its entirety.

FIELD OF THE INVENTION

The present invention relates to systems and methods for depositing thinfilms on a substrate.

BACKGROUND OF THE INVENTION

The use of thin film coated substrates is ubiquitous in today's society.For example, thin film deposition is used for numerous aspects ofconsumer electronics (from integrated circuit fabrication to cell phone,computer and television display coatings), optics (e.g., coating glass),microparticle fabrication, photovoltaic fabrication, and packaging(e.g., aluminum coating on plastic for potato chip bags). In general,thin film deposition can be characterized as the deposition of a thinfilm, or thin layer, of material onto a substrate. Here substrate canrefer to both the base material onto which the thin film is beingdeposited and any previously deposited layers. Thin film deposition canbe split into chemical deposition and physical deposition processes.

Taking the production of solar modules or photovoltaic modules as anexample, this is an area where the quality of the thin films and theexpense and efficiency of producing the photovoltaic modules with thethin films are all significant in producing a commercially viableproduct. Numerous methods have been used for thin film deposition inphotovoltaic module production, such as chemical vapor deposition (CVD)processes, including plasma-enhanced chemical vapor deposition (PECVD),and physical vapor deposition processes, including sputter depositionand evaporative deposition. While there has been significant developmentand improvement of thin film deposition processes for photovoltaicmodule production, any process can benefit from improved filmuniformity, lower material waste and reduced downtime.

Taking one of these processes as an example, referring to FIG. 1 andFIG. 2 there are sectional views of an exemplary evaporative depositionsystem 1000 that could be used for thin film deposition duringphotovoltaic module production. This evaporative deposition system 1000could be used for a closed space sublimation (CSS) or heated pocketdeposition (HPD) process. The evaporative deposition system 1000 shownin FIG. 1 and FIG. 2 includes a source 1100 that contains a depositionmaterial 1200. The source 1100 is disposed within a vacuum chamber (notshown). In FIG. 1, a substrate transport 2000 is shown which isconfigured to carry and position a substrate 3000 over the source 1100.FIG. 2, which is a sectional view orthogonal to that of FIG. 1, showsthe substrate transport 2000 holding the sides of substrate 3000carrying the substrate into (or out of) the paper.

In operation, the source 1100 is heated sufficiently such that thedeposition material 1200 reaches a sublimation point. At the sublimationpoint, particles 1210 of the deposition material 1200 separate and entera vapor pocket 1300. Optimally, the particles 1210, or vapor 1210, willtravel through the vapor pocket 1300 and condense evenly across thesurface of substrate 3000 forming a thin film. In order for this tooccur, two conditions must occur (1) the energy of a particle 1210 mustbe low enough so that it does not continue to bounce off the substrate3000; and (2) the surface temperature of the substrate 3000 must be lowenough to absorb the latent heat within the particle 1210. However,numerous factors can negatively impact the quality of the thin film andthe efficiency of the process.

For example, in current evaporative deposition systems 1000 the walls1110 of the source 1100 are vertical. As a result (a) thermal energyradiated directly to the substrate 3000 heating the edges of thesubstrate 3000 near the walls 1110; and (b) a particle 1210 whichimpacted the vertical side wall would gain energy. These affects wouldmake it less likely for a particle 1210 to deposit near the edges of thesubstrate 3000 resulting in the deposition of a non-uniform thin film.

In addition, it should be recognized that the substrate 3000 can deformunder its own weight and/or bow due to thermal gradient through thethickness of the substrate 3000. Elevated temperatures in certainprocess conditions can further accentuate these problems. For purposesof illustration, this deformation is shown in exaggerated form inFIG. 1. Due to the deformation of the substrate 3000 there needs to besufficient clearance between the substrate transport 2000 and the source1100. However, this clearance creates a gap 1120 between the substrate3000 and the source 1100 where particles 1210, or vapor 1210, can escapeand deposit on other portions of the vacuum chamber (not shown). Thiscauses multiple sources of inefficiency, such as material loss,increased costs for cleaning surfaces inside the vacuum chamber, andlost production time when the process is shutdown for cleaning.

Although present devices are functional, they are not sufficientlyaccurate or otherwise satisfactory. Accordingly, a system and method areneeded to address the shortfalls of present technology and to provideother new and innovative features.

SUMMARY OF THE INVENTION

Exemplary embodiments of the present invention that are shown in thedrawings are summarized below. These and other embodiments are morefully described in the Detailed Description section. It is to beunderstood, however, that there is no intention to limit the inventionto the forms described in this Summary of the Invention or in theDetailed Description. One skilled in the art can recognize that thereare numerous modifications, equivalents and alternative constructionsthat fall within the spirit and scope of the invention as expressed inthe claims.

The present invention can provide a system and method for movably seal avapor pocket in a deposition chamber. In one exemplary embodiment, thepresent invention can include a system for coating a substrate, thesystem comprising a deposition chamber; a vapor pocket located withinthe deposition chamber; and an at least one movable seal, wherein the atleast one movable seal is configured to form a first seal with a firstportion of a substrate, and wherein the first seal is configured toprevent a vapor from leaking past the first portion of the substrate outof the vapor pocket. In some embodiments, the movable seal may comprisea first flange, wherein the first flange forms a wall of the vaporpocket; and a second flange, wherein the second flange is configured tobe movably disposed within a first groove of the source block.

In another embodiment, the present invention can provide a system forcoating a substrate, the system comprising a vapor pocket; a substrate;and an actuator, wherein the actuator is configured to movably seal thevapor pocket with the substrate to prevent a vapor from leaking past thesubstrate out of the vapor pocket. The system may further comprise afirst movable insert, wherein the first movable insert is configured tobe moved by the actuator to form a first seal with a first portion ofthe substrate.

In another embodiment, the present invention may provide a method forcoating a substrate, the method comprising providing a substrate in adeposition chamber; positioning the substrate proximate to a vaporpocket, wherein positioning the substrate forms a gap where a vapor inthe vapor pocket could leak past a first portion of the substrate; andmovably sealing the gap. In one embodiment, movably sealing the gap maycomprise moving a first insert, wherein the first insert contacts thefirst portion of the substrate. In various embodiments, the substratemay be positioned over a source block and the gap may be movably sealedby lowering the substrate, raising the source block, or some combinationthereof.

In yet another embodiment, the present invention may comprise aperimeter mask for thin film deposition, the perimeter mask comprisingan at least one mask surface, the at least one mask surface comprising amask edge, wherein the mask edge is configured to be positionedproximate to a deposition surface; and wherein the at least one masksurface undercuts away from the mask edge. In various embodiments, theperimeter mask may comprise a bezel shape, a parabolic-curve shape, or asegmented curve shape. In some embodiments, the perimeter mask maypartially surround a deposition source, such as a heated-pocketdeposition source, a PECVD deposition source, or a sputter depositionsource.

In yet another embodiment, the present invention may comprise aheated-pocket deposition source comprising a vapor source, wherein thevapor source is configured to heat a deposition material in order toform a deposition vapor; a vapor pocket connected to the vapor source;an aperture, wherein the aperture is configured to allow the depositionvapor to move from the vapor pocket and deposit on a substrate; and anaperture edge, wherein a portion of the aperture edge is formed by anundercut pocket wall.

As previously stated, the above-described embodiments andimplementations are for illustration purposes only. Numerous otherembodiments, implementations, and details of the invention are easilyrecognized by those of skill in the art from the following descriptionsand claims.

BRIEF DESCRIPTION OF THE DRAWINGS

Various objects and advantages and a more complete understanding of thepresent invention are apparent and more readily appreciated by referenceto the following Detailed Description and to the appended claims whentaken in conjunction with the accompanying drawings wherein:

FIG. 1 illustrates a sectional view of typical prior art evaporativedeposition system.

FIG. 2 illustrates an orthogonal sectional view of the evaporativedeposition system in FIG. 1.

FIGS. 3A and 3B illustrate an embodiment of an evaporative depositionsystem with actuators for movably sealing the system.

FIG. 4A illustrates an embodiment of a movable insert that can be usedto form a seal with a portion of a substrate in which the insert is in aclosed position. FIG. 4B illustrates an embodiment of the movable insertin an open position.

FIG. 5 illustrates an embodiment of a movable insert that can be used toform a seal with a portion of a substrate.

FIG. 6 illustrates an exterior side view of an evaporative depositionsystem that can be used consistent with the present invention.

FIG. 7 illustrates an exterior top view of an evaporative depositionsystem that can be used consistent with the present invention.

FIG. 8 illustrates a sectional view of the evaporative deposition systemin FIGS. 6-7 that can be used consistent with the present invention.

FIG. 9A illustrates an isometric view of an evaporative depositionsystem that can be used consistent with the present invention.

FIG. 9B illustrates an enlarged view of one end of the evaporativedeposition system in FIG. 9A.

FIG. 10 illustrates an isometric view of an evaporative depositionsystem that can be used consistent with the present invention.

FIG. 11A illustrates a sectional view of a prior art evaporativedeposition system. FIG. 11B illustrates an exemplary profile of a thinfilm deposited by such a system.

FIG. 12A illustrates a sectional view of an evaporative depositionsystem consistent with the present invention. FIG. 12B illustrates anexemplary profile of a thin film deposited by such a system

FIGS. 13A-13D illustrate exemplary undercut perimeter edge shapes thatcan be used consistent with the present invention.

FIG. 14 illustrates a PECVD deposition system with an undercut perimeteredge consistent with the present invention.

FIG. 15 illustrates a sputtering deposition system with an undercutperimeter edge consistent with the present invention.

FIG. 16 illustrates an embodiment of an evaporative deposition systemconsistent with the present invention which includes a vapor diffuser.

DETAILED DESCRIPTION

Referring now to the drawings, where like or similar elements aredesignated with identical reference numerals throughout the severalviews, and referring in particular to FIG. 3A and FIG. 3B, itillustrates a cross section of an evaporative deposition system 1000consistent with an embodiment of the present invention. As shown in FIG.3A and FIG. 3B, the evaporative deposition system 1000 comprises asource 1100, a substrate transport 2000 for moving and positioning asubstrate 3000 over a vapor pocket 1300, and an actuator 4000 formovably sealing the vapor pocket 1300. In FIG. 3A and FIG. 3B the source1100 is a box or cuboid configured to hold and heat a depositionmaterial 1200. The source 1100 forms a vapor pocket 1300 with thesubstrate 3000 where particles 1210, or a vapor 1210, from thedeposition material 1200 escape during sublimation and can condense onthe substrate 3000 to form a film. The source 1100 in FIG. 3A and FIG.3B is exemplary only and those of skill in the art will readily be awareof alternative shapes and designs that could be used consistent with thepresent invention. For example, in an alternative embodiment the source1100 could have separate chambers or pockets in its base for storing andheating the deposition material 1200 (rather than having a flat base asshown in FIG. 3A and FIG. 3B).

The actuator 4000 in FIG. 3A and FIG. 3B is configured to raise or lowerthe source 1100. For example, in FIG. 3A, the actuator 4000 is in anopen, or lowered, position in order to allow the substrate transport2000 to carry the substrate 3000 over the vapor pocket 1300 whileallowing clearance for the substrate 3000, including any deformation ofthe substrate 3000. As shown in FIG. 3B, once the substrate is inposition over the vapor pocket 1300 the actuator 4000 can movably sealthe vapor pocket 1300 by raising the source 1100 so that the top of thewalls of the source 1100 are proximate to, up to and includingcontacting, the substrate 3000. It is not required that the walls 1110of the source 1100 necessarily contact the substrate 3000 in order toseal the vapor pocket 1300. Instead, the actuator 4000 movably seals thevapor pocket 1300 by moving the source 1100 sufficiently proximate tothe substrate 3000 in order to prevent particles 1210 from escapingbetween the substrate 3000 and the source 1100.

While the substrate 3000 is in a horizontal position in FIG. 3A and FIG.3B, nothing in the present invention limits the application of thisinvention to such an embodiment. Those of ordinary skill in the art willunderstand how to modify and adapt the present invention to othersubstrate 3000 and source 1100 configurations.

In some embodiments of the present invention, an insulator (not shown)can be used between the source 1100 and the substrate 3000. The source1100 is typically maintained at an elevated temperate, commonly rangingfrom 200-700 degrees C., in order to heat the deposition material 1200.Moreover, the walls of the source 1100 are also maintained at anelevated temperature in order to prevent deposition on the walls.Because the substrate 3000 must be maintained at a lower temperature topromote particle 1210 condensation on the substrate 3000, it can bebeneficial to reduce thermal transfer between the substrate 3000 and thesource 1100. Reducing thermal transfer between the substrate 3000 andthe source 1100 promotes film growth uniformity by reducing temperaturedifferences across the substrate 3000. Moreover, in some embodiments thematerial composition of the substrate 3000 may require insulation toprevent a high temperature source 1100 from negatively impacting thesubstrate structure due to contact. An insulator (not shown) could beused to accomplish these and other functions.

In some embodiments, such as is shown in FIG. 3A and FIG. 3B, theactuator 4000 could comprise hydraulic lifts configured to raise andlower the source 1100. In another embodiment, an actuator can beconfigured to raise and lower a substrate transport 2000 for transportand sealing. Numerous options exist depending on the type of substratetransport being used. For example, in one embodiment the substratetransport 2000 may comprise a track system with belts which guide thesubstrate 3000 through the device. These belts may be supported on railsthat can be raised and lowered for transport and sealing. Those of skillin the art will be readily aware of alternative design options. It maybe necessary or beneficial to use an insulator (not shown) between thesource 1100 and the actuator 4000.

FIG. 4A and FIG. 4B shows another embodiment of the present invention,wherein a movable seal or movable insert 5000 is configured to form aseal with the substrate 3000. Given the weight of the source 1100, itmay be preferred in some instances to move a relatively small insert5000 rather than the entire source 1100. It is noted that it in someembodiments it may be preferred to use both an actuator 4000 to move thesource 1100 and the movable inserts 5000 described here to seal againstthe substrate 3000. It is also noted that in some embodiments thesubstrate transport 2000 can be configured to move the substrate 3000 inorder to form the seal with the source 1100.

The actuator 4000 in FIG. 4A and FIG. 4B can be used lower (open) orraise (close) the movable insert 5000. The movable insert 5000 in FIG.4A and FIG. 4B comprises a flange 5100 used to block particles fromentering the open space 5200 formed between the movable insert 5000 andthe source 1100 when the movable insert 5000 is in a closed (or sealed)position. The actuator 4000 may be attached to, or separated from thesource 1100. Depending on the construction of the actuator 4000, thermalconcerns may encourage the use of insulation between the source 1100 andthe actuator 4000.

The view shown in FIG. 4A and FIG. 4B is a sectional view of the movableinsert 5000. In one embodiment, the movable insert 5000 could extend thewidth of substrate 3000 between the portions of the substrate transport2000 which are holding the substrate 3000. In another embodiment,multiple movable inserts 5000 could be used to extend along that length.The movable insert 5000 forms a seal with a portion of the substrate3000 and prevents particles from escaping past that portion. In order toprevent any particles or vapor from escaping the vapor pocket 1300 theperimeter of the substrate 3000 must be sealed. Taking a rectangularsubstrate as an example, movable inserts 5000 can be used to seal oneside or multiple sides of the rectangular substrate. In one embodiment,the substrate transport 2000 can be configured to fit against, or form aseal with, the source 1100 on two sides of the rectangular substrate. Ifthe rectangular substrate were deformed, the deformation will be morepronounced closer to the middle of the rectangular substrate than theedges. Movable inserts 5000 on the remaining two sides of the vaporpocket 1300 could be configured to lower sufficiently to allow thesubstrate 3000 to move over the vapor pocket 1300 and then rise in orderto form a seal with the remaining two edges of the rectangularsubstrate, forming a seal around the vapor pocket 1300.

A movable insert 5000 may also be configured such that the shape of theupper surface of the movable insert 5000, where the movable insert 5000forms a seal with the substrate 3000, more closely matches the shape ofthe substrate 3000. For example, if the portion of the substrate 3000that forms the seal with the movable insert 5000 is non-linear, such asbecause of deformation due to process conditions or because thesubstrate is intentionally non-linear, the movable insert 5000 can beconfigured to more closely match against that shape.

In order to prevent deposition on the movable insert 5000 it may also beconfigured to promote thermal transfer from the source 1100. Forexample, the design and material properties (including the compositionof the material and the directional thermal transfer properties of thematerial) of the movable insert 5000 can all be adapted to promotethermal transfer. FIG. 5 shows one embodiment of a movable insert 5000and actuator 4000 design to promote thermal transfer between the source1100 and the movable insert 5000.

As shown in FIG. 5 the movable insert 5000 may include multiple flanges5110, 5120, 5130, 5140. In this case, a first flange 5110 is used asdiscussed above to help create a barrier between the vapor pocket 1300and the open space or gaps 5200 formed between the movable insert 5000and the source 1100. Guide flanges 5120, 5130, 5140 are used to helpguide movement of the movable insert 5000 and to increase surface areafor thermal transfer between the source 1100 and the movable insert5000. In the embodiment in FIG. 5, one of the guide flanges 5130 isconfigured to rest against an actuator 4000, here an actuator cam 4100,for opening and closing the movable insert 5000.

A movable insert 5000 may be comprised of a material that both promotesheat transfer and minimizes thermal expansion. For example, for theembodiment discussed relative to FIG. 5 the flanges 5100 of the movableinsert 5000 must be configured to fit closely with source 1100 in orderto promote heat transfer and prevent particles from entering betweengaps. But the flanges 5100 must also have sufficient tolerance that anyexpansion due to elevated temperatures will not cause the flanges 5100of movable insert 5000 to become lodged in the source 1100. Possiblematerials include graphite, extruded graphite, isomolded graphite,titanium, thermally conductive ceramics and tungsten. Designconsiderations, operational conditions and cost are all importantfactors as those skilled in the art select a proper material.

The actuator cam 4100 in FIG. 5 is configured such that it can raise orlower the movable insert 5000 through rotation. In this embodiment, theactuator cam 4100 is disposed within a conduit 1130 in source 1100. Thesize of the conduit 1130 may be selected to help reduce thermal transferbetween the source 1100 and the actuator cam 4100. In addition, thematerial selected for the actuator cam 4100 should be able to withstandrepeated operations and operate under the thermal conditions. Forexample, stainless steels or ceramics may be potential materials for thecam 4100.

Now referring to FIGS. 6-8 there is an embodiment of an evaporativedeposition system 1000 consistent with the present invention. FIGS. 6-7show an exterior view of the evaporative deposition system 1000 withsource 1100, substrate transport 2000, and the rotary flex cable 4110for the actuator cam 4100. One advantage of the actuator cam 4100 isthat it allows for a thin rotary flex cable 4110 to be used. Given thecomplexity of deposition systems, and the operation conditions, it isadvantageous to be able to minimize the size and number of parts thatneed to be close to the source 1100.

The top view in FIG. 7 is shown looking down on substrate 3000,substrate transport 2000, source 1100, rotary flex cable 4110, andmovable insert 5000. Sectional view A-A, shown in FIG. 8 depicts anembodiment of a movable insert 5000 consistent with the presentinvention. In this embodiment an undercut flange 5150 serves as a wallfor vapor pocket 1300. As shown, the undercut flange 5150 isundercut—that is, the surface of the undercut flange 5150 which facesthe vapor pocket slants away from where the movable insert 5000 forms aseal with substrate 3000. The benefits of an undercut design arediscussed in greater detail below. In addition to being undercut, theundercut flange 5150 is also configured such that it extends into apocket 1140 of source 1100. Extending the length of the innermostflange—here undercut flange 5150—protects against any depositionmaterial getting into gaps 5200 between movable insert 5000 and source1100. As shown in FIG. 8 the undercut flange 5150 has sufficient lengththat when the movable insert 5000 is in a raised or sealed position theundercut flange 5150 still protrudes into the source 1100.

FIGS. 9A, 9B and 10 show further isometric views of an embodimentconsistent with the present invention. Referring first to FIG. 9A, itshows a cut way view of an exemplary evaporative deposition system 1000.In this example, two movable inserts 5000 are used at each end of thesource 1100 in order to form seals with substrate 3000. FIG. 9B shows anenlarged view of one movable insert 5000. As shown, the movable insert5000 has four flanges 5110, 5120, 5130, 5140 for promoting heattransfer, guiding motion, and protecting against deposition materialgetting into gaps between the movable insert 5000 and source 1100.

FIG. 10 further displays the actuator 4000 used for lowering and raisingthe movable insert 5000. As shown, the embodiment in FIG. 10 employs anactuator cam 4100 with multiple, separate, points of contact 4200 beingused to act against one of the flanges 5100 on the movable insert 5000.Reducing the contact surface area between the actuator 4000 and themovable insert 5000 can help in reducing thermal transfer. However, inother embodiment the point of contact could be extended along the entireedge of the flange 5100. Many design options will be readily understoodby a person skilled in the art.

Now referring to FIGS. 11 and 12 illustrated are exemplary thin filmsdeposited in an evaporative deposition system 1000 with straight walls1110 (FIG. 11A) and an evaporative deposition system 1000 with anundercut perimeter mask 6000 (FIG. 12A). In FIG. 11A the straight wallson the evaporative deposition system 1000 (a) radiate thermal energy onto the substrate 3000 heating the edges of the substrate 3000 near thewalls; and (b) reflect off particles 1210 which impact the vertical sidewall, adding energy to these particles 1210 and allowing the particles1210 to reflect toward the substrate 3000. As a result, it less likelyfor a particle 1210 to deposit near the edges of the substrate 3000, anda greater number of particles are directed toward the center of thesubstrate resulting in a non-uniform thin film 1220. In FIG. 12A, whichillustrates an embodiment consistent with the present invention, thewalls are undercut in order to both (a) reduce the thermal energyradiated from the walls onto the substrate 3000; and (b) redirectimpinging particles back toward the bottom of the source 1100 (ratherthan allowing the particles 1210 to bounce toward the substrate 3000).This results in a more uniform thin film 1230.

As shown in FIG. 12A, the undercut mask 6000 includes a mask surface6100 which undercuts away from the substrate 3000. The mask surface 6100includes a mask edge 6110 which is configured to be proximate to, up toan including touching, the surface of the substrate 3000. In FIG. 12Athe mask edge 6110 is at the tip of a bezel formed by the mask surface6100 and a portion of the undercut mask 6000 that contacts the substrate3000. This is exemplary only. It should be understood that the mask edge6110 need only be a portion of the mask surface 6100 which is proximateto the substrate 3000. Those of skill in the art will readily be awarefor configurations consistent with the present invention.

The undercut shape shown in FIG. 12A is exemplary only. Further examplesof undercut shapes include curves (e.g., FIG. 13A and FIG. 13B), such asa parabolic curve (e.g., FIG. 13B), or straight-line arcs (e.g., FIG.13C). Those of skill in the art will be readily aware of other shapesbased on the present invention. Similarly, for FIG. 12A the angle 6200of the undercut can be changed based on process factors, manufacturingissues, or other conditions. For example, exemplary angles 6200 couldinclude angles between 15 degrees and 75 degrees, wherein the angle 6200is measured between (a) a perpendicular vector to the deposition surfaceand (b) the surface of the undercut wall. It is further notable that theshape of the undercut in an undercut mask 6000 does not need to beuniform. For example, for a vertical or slanted application of anundercut mask the undercut shape near the top of the mask 6000 may bedifferent than the undercut shape near the bottom of the mask. FIG. 13Dshows a slanted embodiment of an undercut mask 6000 wherein the upperportion of the mask 6000 comprises a different shape than the lowerportion 6000.

Use of an undercut perimeter mask is not limited to an evaporativedeposition system. An undercut perimeter mask may provide benefits forother types of thin film deposition systems, such as PECVD systems orsputtering systems. FIG. 14 shows a sectional view of an undercutperimeter mask 6000 for use in a PECVD system 7000. In this embodiment,the undercut perimeter mask 6000 is configured to be proximate to asubstrate 3000. The substrate 3000 may be on a substrate transportsystem 2000, such as a track system, or on a substrate stand (e.g., seesubstrate stand 2200 in FIG. 15). In some embodiments it may bepreferential for the undercut perimeter mask 6000 to be lowered, or thesubstrate 3000 raised, in order to create a seal between the undercutmask 6000 and the substrate 3000. In application, the undercut mask 6000will be disposed within a vacuum chamber (not shown). In someapplications, the undercut perimeter mask 6000 can be integrated withthe walls of the vacuum chamber.

For the PECVD system 7000 in FIG. 14, a linear discharge tube 7100,including inner conductor 7110, is configured to provide sufficientpower to ignite a support gas 7200 to form a plasma 7300. The plasma7300 then provides radicals which disassociate feedstock gas(es) 7400into new deposition material which then deposits on the substrate 3000.A waste gas removal system (now shown) can be integrated into theundercut perimeter mask or separately configured. By partiallysurrounding the linear discharge tube 7100 and feedstock gas 7400 thepresent invention can increase material use efficiency, reducedeposition on other surfaces inside the vacuum chamber (reducingoff-time for cleaning) and achieve more uniform surfaces.

In order to prevent deposition on the surfaces of the undercut perimetermask 6000, the mask may be configured to operate at an elevatedtemperature. For example, in one embodiment a mask 6000 can beconfigured with a heating element (not shown) that provides sufficientheat to the surfaces of the mask 6000 to reduce or prevent deposition onthose surfaces. Based on the elevated temperature of the mask 6000, themask may include an insulator (not shown) which is positioned to contactthe surface of the substrate 3000—protecting the substrate from contactheating.

In another embodiment, the undercut perimeter mask 6000 can be usedwithin a sputter deposition system 8000. FIG. 15 shows an embodiment ofthe present invention where an undercut perimeter mask 6000 is used witha planar magnetron 8100, including planar cathode and planar target.Those of skill in the art will understand modifications that may be madefor other sputtering systems such as a rotatable magnetron system. InFIG. 15 the sputtering deposition system 8000 includes a substrate stand2200 which is configured to raise or lower a substrate 3000 such thatthe substrate is proximate to, up to and including touching, theundercut perimeter mask 6000. This allows for a seal between thesubstrate 3000 and the undercut perimeter mask 6000. As discussed above,the undercut perimeter mask 6000 can be configured to operate at anelevated temperature. Accordingly, in some embodiments an insulator (notshown) may be included to reduce contact heating between the undercutperimeter mask 6000 and the substrate 3000.

It should be further noted that the shape of the mask 6000, as itcontacts the substrate 3000, can vary based on application. While thefigures above show sectional views, this sectional view could be theside view of a rectangular undercut perimeter mask, a circular undercutperimeter mask, an oval undercut perimeter mask, etc. Those of skill inthe art will be readily aware of different shapes and configurationsconsistent with the present disclosure.

It is also noted that the undercut perimeter mask 6000 can beincorporated and combined with other design features. For example,referring now to FIG. 16 it shows an embodiment of the present inventionwhich further includes a vapor diffuser 9000. The vapor diffuser 9000includes at least one aperture 9100, and here multiple apertures 9100,configured to allow particles 1210, or vapor 1210, to move from thevapor pocket 1300 and deposit on the substrate 3000. Those of skill inthe art will recognize that the apertures 9100 can be evenly spaced andsized, or the spacing and size of the apertures 9100 may differdepending on the position of each aperture in order to promote moreuniform deposition. Moreover, in some embodiments the aperture(s) 9100size and position may be fixed or it may be variably controlled. In FIG.16 the internal wall 9200 of the vapor diffuser 9000 is undercut inorder to promote improved thin film deposition. While not shown in FIG.16, it is further notable that this embodiment could be modified tofurther include a movable insert 5000.

Nothing in the present description should suggest that a movable insert5000 is limited to linear motion, or vertical or horizontal motion inorder to movably seal the vapor pocket. In some embodiments, the movableinsert 5000 may be designed to follow an angled path, an arced path, orsome other path in order to form a seal. For example, if a movableinsert 5000 were added to the system shown in FIG. 16, it may bedesigned to move at an angle substantially parallel to the undercut wall9200 of the vapor diffuser. Similarly, for other systems using anundercut perimeter mask 6000 the shape and motion of the movable insert5000 may vary to best fit the configuration of the mask 6000 and otherdesign constraints. The present disclosure is exemplary and those ofskill in the art will be aware of many design options consistent withthe present invention.

Those skilled in the art can readily recognize that numerous variationsand substitutions may be made in the invention, its use and itsconfiguration to achieve substantially the same results as achieved bythe embodiments described herein. Accordingly, there is no intention tolimit the invention to the disclosed exemplary forms. Many variations,modifications, and alternative constructions fall within the scope andspirit of the disclosed invention as expressed in the claims.

What is claimed is:
 1. A method for coating a substrate, the methodcomprising: situating the substrate in a deposition chamber of a system,the system comprising: the deposition chamber; a vapor pocket locatedwithin the deposition chamber; a source block to provide an amount ofheat to generate a vapor for the vapor pocket; and at least one movableseal thermally connected to the source block and configured to form afirst seal with a first portion of the substrate and to prevent thevapor from leaking past the first portion of the substrate out of thevapor pocket, wherein the at least one movable seal comprises: a firstflange forming a wall of the vapor pocket; a second flange configured tobe movably disposed within a first groove of the source blockpositioning the substrate proximate to the vapor pocket and forming agap between the vapor pocket and the first portion of the substrate; andmovably sealing the gap.
 2. The method of claim 1, wherein movablysealing the gap comprises moving the at least one movable seal, whereinthe at least one movable seal contacts the first portion of thesubstrate.
 3. The method of claim 2, further comprising: positioning thesubstrate when the at least one movable seal is in an open position,wherein positioning the substrate forms the gap between the at least onemovable seal and the first portion of the substrate; and moving the atleast one movable seal to a closed position in order to seal the gap. 4.The method of claim 3, wherein the system further comprises a rotatablecam, wherein the rotatable cam contacts an end of the second flange; andwherein the method further comprises rotating the rotatable cam to movethe at least one movable seal between the open position and the closedposition.
 5. The method of claim 1, wherein positioning the substrateproximate to the vapor pocket comprises positioning the substrate overthe source block; and wherein movably sealing the gap comprises liftingthe source block.
 6. The method of claim 1 wherein positioning thesubstrate proximate to the vapor pocket comprises positioning thesubstrate over the source block; and wherein movably sealing the gapcomprises lowering the substrate.
 7. The method of claim 1 whereinpositioning the substrate proximate to the vapor pocket comprisespositioning the substrate under the vapor pocket; and wherein movablysealing the gap comprises raising the substrate.